Thiocyclobutanones



United States Patent 3,345,402 THIOCYCLOBUTANONES James C. Martin, Kingsport, Tenn., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New York No Drawing. Filed July 1, 1963, Ser. No. 292,126

Claims. (Cl. 260488) This invention relates to organic chemistry. More particularly this invention relates to novel chemical compounds and to a novel method for their preparation.

The novel chemical compounds of the invention are thiocyclobutanones of the formula:

R R3('3C=O R S( H H-R wherein R can be an alkyl radical of 1 to about 12 carbon atoms, a mononuclear 'carbocyclic aryl radical having up to about 12 carbon atoms, an acycloxyalkylene radical of the formula:

' R and R can be the same or different and can be hydrogen, alkyl radicals having up to about 8 carbon atoms, mononuclear carbocyclic aryl radicals having up 3,345,402 Patented Oct. 3, 1967 ice The novel compounds can be prepared by the process of the invention which comprises combining a ketene of wherein the substituents R R and R have the meanings previously discussed; R can be the radical R a vinyl radical or a hydroxy alkylene radical of the formula HOtC H- and R and the integer m' have the meanings previously assigned to them.

Typical of the ketenes which are useful in the process of the invention are ketene; aldoketenes such as methyl ketene, ethyl ketene, propyl ketene, butyl ketene, pentyl ketene, heXyl ketene, heptyl ketene, phenyl ketene, 2-

ethylhexyl ketene, octyl ketene, etc.; and ketoketenes such as dimethyl ketene, diethyl ketene, ethylrnethyl ketene, butylethyl ketene, tetramethylene ketene, pentamethylene ketene, diphenyl ketene, methylphenyl ketene, etc.

Useful vinyl thioethers in the process of the invention are compounds such as methyl vinyl sulfide, ethyl vinyl sulfide, propyl vinyl sulfide, butyl vinyl sulfide, pentyl vinyl sulfide, isobutyl v'inyl sulfide, ethyl-l-propenyl sulfide, divinyl sulfide, phenyl vinyl sulfide, ethanol, 2-vinyl thioethylacetate, etc.

The process of the invention can be carried out over a wide temperature range but the preferred temperature. is from about 0 C. to about 180 C. In the case of ketene, diphenyl ketene and the lower' monoalkyl and dialkyl ketenes temperatures of about 20 C. to about 40 C. are the most preferred. Temperatures above about N 40 C. are frequently preferred for the less reactive to about 12 carbon atoms or can collectively represent joined alkylene radicals which, together with the common carbon atom to which they are attached, form a saturated'carbocyclic ring of 5 to 7 ring carbon atoms as in tetramethylene ketene, pentamethylene ketene, hexamethylene ketene, etc.; R is a hydrogen atom or a lower alkyl radical having up to about 4 carbon'atoms and each of m and n is an integer from 1 to about 4. The integers m and n are preferably 1 or 2.

R when an alkyl radical of 1 to about 12 carbon atoms is typically a radical such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, nonyl, decyl, undecyl, dodecyl, etc. and is preferably a lower alkyl radical, i.e., sucha radical having up to about 4 carbon atoms.

.R and R when alkyl radicals of 1 to 8 carbon atoms, are typically radicals such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, etc., and are preferably lower alkyl radicals, i.e., such radicals havin'gup to about'4 carbon atoms.

"R R and R can also be mononuclear aryl radicals such as phenyl or lower alkyl substituted phenyl radicals having up to about 12 carbon atoms, including such radicals having more than one lower alkyl substituent presentonthe phenyl-ring. The loweralkylsubstituents have 1 to about 4- carbon atoms. 7

7 65 solution 'is distilled to recover a considerable amount of a group which reacts. with the ketene, e.g.,

higher ketoketenes. The process can be conducted with.

or without an inert solvent. Suitable solvents for use in the process of the invention include ethers, chlorinated hydrocarbons, esters, aliphatic hydrocarbons, aromatic hydrocarbons, etc.

. The reactants are normally combined in a 1:1 molar ratio. However, the process can be carried out with an excess of the ketene or of the vinyl thioether. In the event the vinyl thioether contains another functionala hydroxy group or'a vinyl group, moles of ketene per mole of vinyl thioether.

. The following examples illustrate and process of the invention.

011 0 O CHzCHzS-CH-CH To a stirred solution of 146 g. (1.0 mole) of 2-vinyl thioethanol, acetate in 300 ml. of hexane under nitrogen is added 7 0 g. (l.0 mole) of dimethylketene. After stirring for 24 hr. at room temperature, the reaction it is frequently desirable to employ two" the novel compounds Z-Vinylthioethanol, acetate and 88.5 g. (41%) of 3-(2- acetoxyethylthio -2,2-dimethylcyclobutanone.

The 3-(2-acetoxyethylthio)-2,Z-dimethylcyclobutanone prepared by this method has a B.P. of 119124 C. (1.5 mm.), exhibits a strong infrared absorption at 565g, characteristic of cyclobutanones and has the following analysis:

Calcd. for (3101311 80 C, 55.5; N, 7.4; S, 15.2.

Example 2 C, 55.6; H, 7.4; S, 14.8. Found:

To a stirred solution of 37 g. (0.5 mole) of methyl vinyl sulfide in 150 ml. of ethylacetate is added 35 g. (0.5 mole) of dimethyl ketene at room temperature. After stirring for hr. at room temperature, the reaction solution is distilled through a 10-in. packed column to give 45.5 g. (63%) of 2,2-dimethyl-3-(methylthio)cyclo butanone.

The 2,2-dimethyl 3 (methylthio)cyclobutanone prepared by this method has a B.P. of 92-95 C. (40 mm.) and exhibits a strong infrared absorption at 5.65 L.

l (i) (OHa)2C-( (CHQMCHCO CHzCHrSCH-CH,

C2H5S-CH (|}HCH3 A solution of 8.2 g. (0.08 mole) of ethyl-l-propenyl sulfide and 10.2 g. (0.081 mole) of butylethylketene in 40 ml. of toluene is refluxed for 6 hr. Examination of the crude reaction solution by infrared shows a strong absorption at 5 .65 1. (cyclobutanone'). The mixture is analyzed by gas chromatography and is found to consist of toluene, ethyl-l-propenyl sulfide, butylethylketene dimer, and the desired product. By use of a preparative scale gas chromatography column 0.5 ml. of the product peak is isolated and shown to be 2-butyl-2-ethyl-3-(ethylthio) -4-methylcyclobutanone.

The 2-butyl-2-ethyl 3 (ethylthio)-4-methylcyclobutanone prepared by this method has the following analysis: Calcd. for C H OS: C, 68.5; H, 10.5; S, 14.0. Found: C, 68.6; H, 10.5; S, 14.2.

Example 5 ll OHaCO CHaCHzSCH-OH A mixture of 24 g. (0.124 mole) of diphenylketene and 18 g. of (0.124 mole) of 2-vinylthioethanol, acetate is allowed to stand for several days. The reaction is exothermic and seems to be almost complete in a few hours. The solution becomes quite viscous and slowly crystallizes. The yield of crude solid having a melting point of 86-89 C. is essentially quantitative. An analytical sample after recrystallization from ethanol melts at 90-91 C. Analysis indicates that this material is 3-(2-acetoxyethylthio)-2,2- diphenylcyclobutanone.

The 3-(2 acetoxyethylthio)-2,2-diphenylcyclobutanone prepared by this method has the following analysis:

Calcd. for C H O S: C, 70.5; H, 5.9; S, 9.4. Found: C, 70.7; H, 6.0; S, 9.5.

Example 6 Using the general method described in Example 4, diethylketene and phenylvinyl sulfide give 2,2-diethyl-3- phenylthio cy clobutanone.

Tlre 2,2-diethyl-3-(phenylthio)cyclobutanone prepared by this method has B.P. of -108 C. (2.5 mm.).

Using the general method described in Example 2, dimethylketene and divinyl sulfide give 3,3'-thiobis(2,2-dimethylcyclobutanone) The 3,3-thiobis(2,Z-dimethylcyclobutanone) prepared by this method has a B.P. of 148-154 C. (5 mm.).

Example 8 CrzHuS-CH-CH:

Using the general method described in Example 2, dimethylketene and dodecylvinylsulfide give 2,2-dimethyl- 3 dode cylthio cycl obutanone.

The 2,2-dimethyl-3-(dodecylthio)cyclobutanone prepared by this method has a B.P. of 106-110 C. (15

Example 9 A solution of 21 g. of ketene and 68 g. of phenylvinylsulfide is heated in a stainless steel autoclave at 150 for 4 hr. Distillation of the reaction solution yields 3- lowing ketenes and vinyl substituted vinyl thioethers react to give the product shown:

i CmHzs-S-CH-CH:

cirru-s-onm The novel compounds of the invention are useful as thermal stabilizers for various polymeric materials, e.g. polyolefins such as polypropylene, and are particularly useful as thermal stabilizers for poly(methylmethacrylate)resins.

The compound to be used as a thermal stabilizer can be incorporated into the polymeric material by milling them together on hot rolls or by other means known to the art.

When the polymerization reaction is not deleteriously affected by the presence of the thermal stabilizer, the stabilizer can be added to the reactants prior to polymerization.

The concentration of the stabilizer is generally about 0.001 to about 3 and preferably about 0.01 to about 1 part by weight per one hundred parts of polymer.

The following example illustrates the use of one of the novel compounds of the invention as a thermal stabilizer for poly(methylmethacrylate) Example 1] Into a glass-lined reaction kettle is charged g. of disOdium acid phosphate, 25 g. of a 1% aqueous solution of the sodium salt of polymethacrylic acid, 10 g. of sodium hypophosphite, 2.2. g. of a,a-azobis(isobutyronitrile). 550 g. of methylmethacrylate, 950 g. of water and 2 g. of 3-(2-acetoxyethylthio)-2,Z-dimethylcyclobutanone. The reaction vessel is heated at 110-125 for several hours. The granular polymer is removed by filtration, washed and dried. The resulting polymer is heat treated in an oven at 125 for 12 hours. The moldings from this material have exceptional clarity. The molding powder shows superior thermal stability.

The invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinbefore and as defined in the appended claims.

I claim:

1. Thiocyclobutanones of the formula:

carbon atoms, (b) a acyloxyalkylene radical of the formula:

and

(c) a cyclobutanone radical of the formula:

R -hG=0 OHC|JHR5 R is selected from the group consisting of:

(a) an alkyl radical of the formula: ruc rn e and (b) a radical of the formula:

R4 it -(Bra R and R are selected from the group consisting of:

(a) hydrogen,

(b) an alkyl radical of 1 to 8 carbon atoms,

(c) a mononuclear aryl radical of up to 12 carbon atoms and (d) joined alkylene radicals which, together with the carbon atom to which they are attached, form a saturated carbocyclic ring of 5 to 7 carbon atoms:

R is selected from the group consisting of: 40 (a) hydrogen and (b) a lower alkyl radical and each of m and n is an integer from 1 to 4.

2. Thiocyclobutanones of the formula:

R4 R3(IJC=O R S( JH('1HR wherein R is selected from the group consisting of (a) a mononuclear aryl radical of up to about 12 carbon atoms,

(b) an acyloxyalkylene radical of the formula:

.1 R -o0mH m 2 and (c) a cyclobutanone radical of the formula:

34 *i -CH-OHR6 group consisting of:

7 8 R is selected from the group consisting of: 3,022,268 2/ 1962 Armitage et a1 260-4585 (21) hydrogen and V 3,189,608 6/1965 Martin 260-586 (b) a methyl radical; in is 2 and n is 1. OTHER REFERENCES 3. 3-(2-acetoxyethy1thio)-2,2-dimethy1cyc1obutanone. 5 4. 3 2 -isobutyry1oxyethylthio) 2,2-dirnethylcyc1offi i Organ Reaflms 1962 butanone. r

5. 3-(2-acetoxyethy1thi0)-2,Z-diphenylcyclobutanone. 2 Chemistry of Orgamc compounds 1939 References Cited 10 RICHARD K. JACKSON, Primary Examiner. UNITED STATES PATENTS LEON I BERCOVITZ LORRAINEA WEINBER ER 4 2,960,532) 11/1960 Gordon et a1 260 -4-76 ExamineGrs 2,964,554 12/1960 Havens et a1 260-476 2,980,646 4/ 1961 Lappin 260-4585 M, J, WELSH, V, GARNER, Assistant Examiners. 

1. THIOCYCLOBUTANONES OF THE FORMULA: 